Generic vehicle braking systems reduce the speed of a vehicle, in particular a car or truck. For this a pedal-actuated brake master cylinder is provided, to which at least two brake circuits are connected. The two brake circuits each lead to two associated wheel brakes. When the driver actuates the brake pedal, a mechanical force thus exerted is converted into a hydraulic force which in turn causes an increase of the brake fluid pressure at the wheel brakes. In the known fashion, this pressure is additionally increased or reduced by means of a hydraulic assembly with which also functions of an antilock braking system (ABS) and/or electronic stability programme (ESP) can be implemented. For this, a plurality of pumps is provided in the hydraulic assembly, by means of which the brake fluid pressure in the individual brake line portions of the associated brake circuit is increased or reduced. The individual brake line portions are isolated by means of hydraulic valves which can usually be switched electromagnetically. One of these valves is placed in a line connection between the storage reservoir and the suction side of the associated pump, and is generally also called a suction valve or high-pressure switching valve (HSV). When the high-pressure switching valve is activated, it opens a flow path from the storage reservoir to the suction side of the pump, so that the pump can actively build up brake fluid pressure which can be passed on to the wheel brakes. To guarantee correct opening and closing of the high-pressure switching valve, this is provided with a valve body which is pressed or tensioned against an associated valve seat by means of a valve spring. The valve body can thus only be lifted actively from the valve seat by the application of force. The opening pressure generated by the valve spring is overcome by means of a solenoid assembly, by means of which the valve body can be moved on switching of the high-pressure switching valve. The opening pressure is normally over 2 bar. The opening pressure is the pressure which must be present at the valve body in order for this to be raised from the valve seat, even without activation by the solenoid assembly, against the force of the valve spring.